Specifications

7-14
INPUT PRIORITY....Selection 3....
INPUT PRIORITY CODES: 1 = Low, 2 = normal, 3 =
high (controller may show 0’s if never programmed, 0 is
the same as 1 functionally)
Assign values of 1-3 to each TP input. Inputs of higher
priority will override those of lower priority. Inputs of the
same priority will be served concurrently, where the first
TP phase achieved will TP hold, then go on to the next,
etc.
Note that a higher priority TP input will cease overriding
lower priority inputs if it’s max wait or fail timer times out.
TRANSIT PRIORITY GROUP TIMING
Transit Priority Group Timing is used to time out non-TP
phases quicker when going to a TP phase. Once the TP
phase(s) is achieved, the normal selected timing re-
sumes, i.e. group timing is not used for the TP phases
themselves.
PRIOR MENU......
TP GRP TIMING....Selection 2....
GRP MAX TIMES...Selection 1....
Range; 0-255 seconds
There are three sets of group max times and one
max time per phase per group. When the group is
selected by Free Mode or CS assignment, the
associated group max time will determine shortest max
time allowed for non-CNA phases when attempting to
time out that phase quicker to get to a transit priority
phase. These max values are typically set shorter than
the normal max or split time* The values are used
directly during TP transition in free operation, but are
only a part of a more complex computation involving
cycle leading limits during coordination (see max value
computation during coord below).
*In coordinated operation, the normally used max is
typically set long enough so that the phase will force off
before maxing out. In the case of going to a transit
priority phase, the group maxes would be set up to be
shorter than the split time so non-transit priority phases
will be allowed to max out before forcing off.
The purpose for several groups is so that different
value TP max times can be used with different cycle
split combinations.
TP MAX VALUE COMPUTATION DURING COOR-
DINATED OPERATION:
Under TP control during coordinated operation, the
max timer values of non-TP phases are actually
computed in consideration of both the GRP MAX TIME
and the CYCLE LEADING LIMIT (see cycle leading limit
set-up). Upon activation of a non-TP phase while an
input is active, the unit will attempt to compute an
appropriate max time such that it will time out exactly at
the cycle leading limit threshold point (force off minus
leading limit value). However, it applies the restriction
that this value cannot be less than group max time.
Thus, the longer of these two concerns takes prece-
dence. If the phase has not begun timing, the max is
initialized to the computed value on phase start up. If it
is already timing, the max timer is dynamically
corrected.
Example of TP MAX value computation
Say for a non-TP phase about to be terminated due to a
TPr input (for another phase);
-The phase’s normal max value is 30
-The phase’s selected TP GP max is 15.
-The phase normally forces off at 60 seconds (in the
active cycle/split)
-The cycle leading limit for the active TPr input is 10
seconds (the cycle leading limit threshold is then at
50 seconds since the force off is at 60).
-Scenario 1. Say when the transit priority input
becomes active the current cycle timer is at 55 while the
phase’s max timer is at 20 (max timers time down).
--TRANSIT PRIORITY SET-UP--
1. TP INPUT SET-UP 3. TP FREE MODE
2. TP GRP TIMING 4. TP COORD OPTIONS
TP INPUT 1 2 3 4 5 6
PRIORITY 1 2 3 3 3 3
PHASE 1 2 3 4 5 6 7 8
GP1 MAX 22 18 0 0 0 0 0 0
GP2 MAX 26 20 0 0 0 0 0 0
GP3 MAX 30 22 0 0 0 0 0 0
--TRANSIT PRIORITY GROUP SET-UP--
1. GRP MAX TIMES
2. GRP WLK TIMES